Range and view finder system for cameras



April 4, 1939. J, MIHALYI RANGE AND VIEW FINDER SYSTEM FOR CAMERAS FiledAug. 1, 1936 Jose Patented Apr. 4, 1939 UNITED STATES RANGE AND VIEWFINDER SYSTEM FOR CAMERAS Joseph Mihalyi, Rochester, N. Y., assignor, by

,mesne assignments, to

pany, Jersey City, N. Je

rsey

Eastman Kodak Com- J., a corporation of New Application August 1, 1936,Serial No. 93,824

1 Claim.

My present invention relates to photographic cameras provided with rangeand view finder systems, and more particularly to an improvedconstruction for a combined range and view finder 5 system.

In providing cameras with range finders and view finders it has beencustomary to couple the movable part of the range finder with thefocusing adjustment of the camera, so that the cam- 10 era is always infocus for the distance at which the range finder is adjusted. Manyarrangements have been proposed whereby the view finder is mounted withits observation window near to the observation window of the rangefinder, so" that the observer need shift his eye but a small amount inchanging from the view finder to the range finder. It has also beenproposed in connection with base type range finders to so construct themthat one of the range finder 2 beams is simultaneously employed forshowing the field of view. However, such an arrangement requires specialrange finder optical parts,

and in some cases it is not conducive to an exact functioning of therange finder.

It is an object of my invention to provide a combined range and viewfinder system which is particularly adapted for mounting on a camera andwhich makes use of a common ocular or observation window for both therange finder so and the view finder.

Another object of my invention is to provide a combined range and viewfinder system which is so constructed and arranged that the user mayObserve through a single observation window, both the range finderimages andthe view finder image, either simultaneously or selectively.

Other objects and advantages of my invention will appear from thefollowing description when read in connection with the accompanying 40drawing, and its scope will be pointed out in the appended claim.

In the drawing forming a part of this disclosure:

Fig. 1 is a view in perspective of the optical parts of one form whichmy invention may take.

Fig. 2 shows the combined view finder and range finder fields asobserved through the arrangement shown in Fig. 1.

Fig. 3 is a view in perspective of an arrange-.

ment similar to Fig. 1, but modified for observing selectively the rangeand view finder fields.

Fig. 4 is a perspective view showing a motion picture camera providedwith a combined range and view finder system of my invention.

5 Fig. 5 shows the field of view as seen through the view finder ofFigs. 3 and 4, and,

Fig. 6 shows the field of view as observed through the range findersystems shown in Figs. 3 and 4.

According to the invention, a base type range finder, including twospaced beam collecting members and a beam combining unit, is providedwith an ocular or viewing window having an axis perpendicular to thebase line of the range finder. A view finder is also provided with anoptical axis which substantially coincides with the ocu lar axis of therange finder, whereby the range and view finder fields are viewedthrough a single ocular or observation opening.

In Fig. 1, one form of the invention is illustrated as comprising twospaced light deflecting elements, such as right-angled prisms ill and H,which, in a well known manner, accept two spaced beams of light anddirect them along the base line formed by the members I0 and H. Forcombining these two beams there is provided between the members it and Il and in the base line of the range finder, a beam combining unitcomprising rlghtangled prisms I2 and i3 which receive the rays directedthereto by the end members l0 and i I, respectively, and direct themthrough an additional right-angled prism M, which, in turn, directsthese beams rearwardly through an observation window, such as thatformed by an ocular lens 15.

It will be evident that the prism assembly l2, l3 and it constitutes amodified porro prism erecting system and functions in a well knownmanner. Although the range finder just described may be of the zeromagnification type, I prefer to make it telescopic, as shown in Fig 1,by providing objective lenses I6 and I! in the base line of the finder,and these obiectives areof such focal length as to form their respectiveimages on the face of the prism l4, to which the prisms l2 and iii arecemented. The Junction of the adjacent edges of the prisms l2 and 13thus forms a dividing line between the upper and lower fields of therange finder, and this divided image is viewed'th'rough the prism It bymeans 'ofthe ocular 15 which thus. becomes the eyepiece for theobjective lenses l6 and H.

In accordance with my invention, I also employ the ocular I 5 as theeye-piece of a view finder, and such an arrangement is provided bycementing to the upper reflecting surface of the prism M, which ishalf-tone plated, a rightangled prism l8, which cemented surface, as iswell known, forms asemi-transparent, semi-rethe arrangements shown inthe observer somewhat fleeting surface. On the front surface of theprism II, I position a lens element 19 which becomes the field lens of aview finder, having the ocular l5 as its eyelet lens. The view finderfield lens I! may be spaced in front of the prism It, but I prefer tocement it thereto so as to provide a more compact construction and toreduce light losses due to air glass surfaces.

In the arrangement above described, the field of view will be visible toan observer through the ocular II, the semi-transparent surface betweenthe prisms i4 and II and the view finder field lens 19. There will alsobe visible to the observer through the ocular I! and the semi-reflectingsurface between the prisms i4 and 19, the range finder images formed bythe objective lenses i6 and I1. These two sets of images will appear toas is shown in Fig. 2, the entire frame defining, without mutilation,the field as seen through the view finder, and the mutilated image ofthe steepled building being defined by the dividing line passinghorizontally through the frame. The telescopic action of the rangefindei' greatly enlarges the range finder image relatively to the viewfinder image, so that confusion between the two is avoided.

when the combined range and view finder system described in connectionwith Fig. 1 is mounted on a camera, the focusing adjustment of thecamera is preferably coupled to the range finder in some well knownmanner, and for this purpose I have shown the objective lens 11 mountedin a pivoted member 20 which is provided with a link member 2| forcoupling it to the camera focusing adjustment. One suitable couplingarrangement is shown in my Patent No. 1,991,110, although it will beobvious that any other suitable coupling may be employed.

The form of the invention illustrated in Fig. 3 is functionally the sameas that shown in Fig. 1. In Fig. 3 the several light deflecting membersare shown as comprising suitably arranged mirrors, instead of the prismsshown in Fig. 1. In this arrangement mirrors 22 and 22 define the endsof the base line of the range finder, and the beam combining anderecting system comprises suitably arranged mirrors 24, 29, 29 and 21which combine and direct, through the ocular 29, the imagebearing beamsprovided by the end mirrors 22 and 23 and their associated objectivelenses 29 and 20. As was the case in the arrangement shown in Fig. 1,the ocular 29 also functions as the eyelet lens for the view finder, thefield lens ll of which is positioned in optical alinement with theocular 28 and the mirror 21, which is rendered semi-transparent in anywell known manner. If desired, the semi-transparent mirror 21 may bemade completely reflecting and shiftably mounted so that it may readilybe moved out of the path of the view finder beam of light. The mirror 21may be mounted for sidewise movement, but, for convenience, I prefer toprovide it with a suitable hinged mounting 22, so that it may be swunginto the position shown in Fig. 3 for taking the range finder reading,and then swung to a horizontal position and out of the visual path ofthe view finder when the field of view is to be observed. Thisarrangement permits the use of a simple structure for so swinging themirror 21, and one suitable structure is shown, in section, in thisfigure as comprising a pin member 22 secured to the mirror 21 andextending through an arcuate slot 24 provided in the view finder housing25 in a position convenient to the operator.

While I have shown in Figs. 1 and 3 the beam combining and erecting unitpositioned substantially half way between the members forming the baseline of the range finder, it is to be understood that this unit may beotherwise positioned, such as at one end of the base line. as is shownin my copending application Serial No. 742,242, filed August 31, 1934.

In Fig. 4 I have shown the combined range and view finder system of myinvention applied to a motion picture camera and employing a rangefinder of the type in which the beam collecting and beam combining unitis separate from and spaced in front of the telescope system, so thatthe light passes serially through them, as disclosed and claimed in myPatent No. 2,029,932. In this figure a motion picture camera 38 isprovided on its top side with a longitudinal housing 31 for certainelements of the range finder system. This housing 31 may convenientlyform a support upon which may be mounted a suitable carrying handle 39,in the end members of which are mounted the view finder elements, aswill be described below. The housing 31 is preferably expanded at itsforward end to provide chambers 39 and 40, in which are mountedrespectively the beam accepting light deflecting elements 4| and 42,which are here shown as being prisms. The two beams of light received bythese prisms 4| and 42 are deflected onto coincidence prisms 43 and 44,respectively, which, in turn, direct the two light beams through a doveprism 45 to the objective lens 46 of a telescope having an ocularcomprising two separated lenses 41 and 48. One or both of the beamaccepting prisms 4i and 42 may be coupled to the focusing movement ofthe camera objective as described in my above-mentioned Patent No.2,029,932.

The camera carrying handle 28 is preferably so formed, in a well knownmanner, to carry view finder elements, and is here shown provided with anegative lens 49 in its front hinged plate member and an eyelet opening50 in its rear hinged plate member ill, to form a well known type ofdirect view finder. The rear hinged plate member 5| of the carryinghandle 38 is also provided with a reflecting member 52 which ispreferably hingedly secured thereto by means of a pin 52, so that thereflecting member 52 may be folded into the hinged plate member 5| whenthe camera is not being used. In use, the reflecting member 52 is swungout about the pin 52 to the position shown in Fig. 4, so as to receivethe light emerging from the eyelet opening 50 and to direct itdownwardly to intercept the optical axis of the range finder systembetween the lens elements 41 and 49, forming the ocular thereof. Inorder that this view finder beam of light may be directed through thelens 49 to the eye of the observer, a light deflecting member 54 ispivotally mounted on a pin 55 secured to the walls of the range finderhousing 31. This deflecting or mirror member 54, when in the positionshown in the drawing, completes the view finder system and makes itpossible to observe the fleld of view through the lens 49 and the viewfinder field lens 49. If the light deflecting member 54 is madesemi-transparent, the range and view finder fields may be observedsimultaneously as was the case with the arrangement shown in Fig. 1.However, I prefer to use a light deflecting member 24 which iscompletely reflecting and provide it at its free end with a laterallyextending knob 80 which projects through an arcuate slot 51, provided inthe side wall of the range finder housing 21, so that the operator maymove the deflecting member or mirror 54 to the position indicated inoutline while the range finder is being used, and return it to theposition shown in Fig. 4 when the view finder is to be used.

With the arrangements described in connection with Figs. 3 and 4, usinga movable mirror element 21 or 54 which is fully reflective, the rangefinder field and the view finder field will be observed separately andselectively and will appear to the observer as shown in Figs. 6 and 5.

It will be evident from the several embodiments described above that myinvention is adapted to be used with various types of range finders andview finders, and that it provides a simple and convenient arrangementwhereby the range finder and the view finder may be used simultaneously,or, if desired, it provides an arrangement whereby a single ocular orobservation window may be employed to view alternatively the range andview finder fields by simply altering the position of a single movablemember.

While I have illustrated and described my invention as incorporated inseveral specific embodiments, it will be understood that I do not desireto be limited to these specific constructions, but intend to include allmodifications which fall within the scope of the appended claim.

What I claim as my invention and desire to secure by Letters Patent ofthe United States is:

A combination range and view finder system comprising an observationopening, a view finder field lens in front of said opening andcooperating therewith tov provide at a certain magnification an image ofthe field of view, a base type range finder having spaced beam acceptingelements, beam combining units and including lens means for providingimages at a magnification different from that for the field of view, anda reflecting means for directing the range finder beams through theobservation opening, said refleeting means being semi-transparent andpositioned in light transmitting relation between said field lens andsaid opening, whereby the range finder images and the view finder imageare observable at diiferent magnifications and within one apparentfield.

JOSEPH MIHALYI.

